1. Field
Apparatuses and methods consistent with exemplary embodiments of the inventive concept relate to a transmitter that uses an orthogonal frequency division multiplexing (OFDM) method, a receiver, and controlling methods thereof.
2. Description of the Related Art
Digital Video Broadcasting the Second Generation Terrestrial (DVB-T2) is a 2nd generation Europe terrestrial digital broadcasting standard that has been adopted in 35 or more nations of the whole world including Europe and has improved performance of DVB-T. The DVB-T2 applies the newest technologies, such as a low density parity check (LDPC) code, 256 quadrature amplitude modulation (QAM) method, etc., to realize increase in transmission capacity and high bandwidth efficiency. Therefore, the DVB-T2 may provide various types of high-quality services such as a high definition television (HDTV), etc. in a restricted band.
A T2-frame currently used in the DVB-T2 includes a preamble symbol P1, a preamble symbol P2, and a data symbol. The preamble symbol P1 is used to perform synchronization and transmit signaling data. A receiver detects the preamble symbol P1, performs synchronization by using the detected preamble symbol P1, compensates for frequency offset, and receives the signaling data.
However, a process of detecting the preamble symbol P1 is performed by using a guard interval of the preamble symbol P1. If the process of detecting the preamble symbol P1 is performed based on data, it is difficult to accurately detect a preamble start point within one (1) sample.
Therefore, there has been developed a method of using Zadoff-Chu sequences to accurately detect a preamble start point within one (1) sample.
FIG. 1 is a view illustrating a related art. In detail, a sync signal includes eight Zadoff-Chu sequences 110, and five of the eight Zadoff-Chu sequences 110 are used to transmit the sync signal. Therefore, data is loaded into only three sequences 120 to be transmitted.
A receiver stores several sequences and detects a preamble symbol based on outputs that are respectively correlated to received Zadoff-Chu sequences. Therefore, a structure of the receiver is complicated, and it is difficult to transmit a large amount of data.
Therefore, an information transmission amount in a preamble symbol is required to be increased, a preamble detection performance of a receiver is required to be improved, and complexity of a structure of the receiver is required to be reduced.